Print Preview: Hook up the print button to initiate printing without displaying a print dialog.

content/browser/renderer_host/render_view_host.h

Index: content/browser/renderer_host/render_view_host.h
diff --git a/content/browser/renderer_host/render_view_host.h b/content/browser/renderer_host/render_view_host.h
index cc3bfacac8fe5aa5a76f6fe00120b2b552e97818..9d2fd23ebedf5661d39407a258dda53dec5f49aa 100644
--- a/content/browser/renderer_host/render_view_host.h
+++ b/content/browser/renderer_host/render_view_host.h
@@ -328,8 +328,9 @@ class RenderViewHost : public RenderWidgetHost {
   // Prints the node that's under the context menu.
   void PrintNodeUnderContextMenu();
 
-  // Triggers printing of the preview PDF.
-  void PrintForPrintPreview();
+  // Triggers printing of the preview PDF. |job_settings| is a json string
+  // that contains print job settings information.
+  void PrintForPrintPreview(const std::string& job_settings);
 
   // Copies the image at the specified point.
   void CopyImageAt(int x, int y);